Genetics Combined With Air Pollution Has Been Found to Increase Autism Risk

According to a new study, children who carry a predisposition for autism who are also exposed to high air pollution have a greater risk of developing the disorder.

This predisposition is a variant in the MET gene.

“The MET gene variant has been associated with autism in multiple studies, it controls expression of MET protein in both the brain and the immune system, and predicts altered brain structure and function,” explains Dr. Daniel B. Campbell, senior author of the study.

This new study by the University of Southern California studied 408 children, between the ages of two and five, more than half of whom had some form of autism. They took the children’s blood samples to determine if they carried the MET gene. This data was then combined with regional air quality measurements of places where the children and their mothers had previously lived.

Those children who carried the MET gene and also lived in highly polluted areas were three times more likely to develop autism than those who did not have the risk genotype and lived in places with less air pollution.

This study therefore suggests that air pollution exposure and the genetic variant in the MET gene interact to increase the risk of autism.

“Although gene-environment interactions are widely believed to contribute to autism risk, this is the first demonstration of a specific interaction between a well-established genetic risk factor and an environmental factor that independently contribute to autism risk,” explained Campbell.

Further studies will be conducted on the interaction of air pollution exposure and the MET genotype in mothers during pregnancy.